diff --git a/src/model.cpp b/src/model.cpp
index 8ba5ab5..56bb39b 100644
--- a/src/model.cpp
+++ b/src/model.cpp
@@ -408,8 +408,7 @@ bool Model::insert(ModelData * model_data, bool insert_whole_tree)
 bool Model::insert_tree(bool insert_whole_tree)
 {
 	bool result = false;
-	has_primary_key_set = false; // the key will be overwritten (the database will create a new key)
-	model_env->has_primary_key_set = false;
+	model_env->has_primary_key_set = has_primary_key_set;
 
 	if( insert_whole_tree )
 	{